Drying roll



w. H. GUY

DRYING ROLL May 21, 1957 Filed March 4, 1955 nited States Patent DRYING ROLL Warren H. Guy, Holmes, Pa., assiguor toAmerican Viscose Corporation, Philadelphia, Pa., .a corporation of Delaware;

Application March 4, 1955, Serial No. 492,205 Claims. (Cl; 34-124) The present invention relates to a drying roll which may be used for drying continuously traveling sheets of flexible material such as cellophane. Inparticular, the invention relates to a drying roll which, when heated to a drying temperature,maintains a temperature diflerential between the end and central surface portions of the roll.

In' the production ofcontinuous sheetsofflexible material, such as celloph'ane it' is the generalpracticeto dry the, wet sheets by passing them over a series of rotating hollow rolls which; are internallyheated'by' a suitable heating medium such as steam or hot water. The roll surfaces are of substantially uniform temperature and because of this factor many difficulties are encountered Wh1ch tend to produce sheet products of inferior quality. For instance, when dryingcellophane with these uniform surface temperature rolls, it has been found that the film edge portions are -dried"more rapidly" than the central portion of the=film whereby the final sheet has a non-uniform moisture content, theedge por tions having lessmoisjture than the central portionsof the sheet As a result of this non-uniform drying pattern, the sheet edge portions shrink more rapidly than the central portions of the sheet whereby the final film or sheet'li as curly or floppy edges which are easily torn or ripped cau'sing damage to the sheet. Obvious difliculties are en'-' countered when using such a sheet of nou-uniformstrength' and moisture content in wrapping machines, packaging machines, multicolored printing machines; etc.

Various dryiugmethodS and apparatus have beerr'experimented with an attempt to overcome the 'difiicul ties and disadvantages mentioned above, but Without muchsuccess. For example, efforts haveb'eenmade to me chanically prevent uneven shrinkage oftliefilmr during the drying operation by gripping thefilm"on"either"sidewith suitable clamps which exert a pull'onthesheet'edges away from the center of the sheet'therebycounteracting any rapid shrinkage of the sheet edgepor-tions: However,,it has been found that the clamps tearyripior create weak spots within the edgeportions of the*sheet-or-film.

Therefore, it is one object "of iny invention t o'providea drying roll which will"uniformly-dry' a'continuous sheet traveling thereover to provide a' fiuahproducthaving a" uniform moisture content and a uniform 'shrinkagepao tern.

Another object is to provide a drying roll" whereina temperature differential is maintainedibetween the :end and central portions of the roll surface.

Still another object of my invention is to provide a-drying roll wherein a variety of diiferenttemperaturedifferentials may be provided.

Other objects and advantages will become rmore ap. parent from a study" ofthe following. desoriptiomand. drawings wherein:

Figure 1 is a View partially sectioned of the dryingroll 1' showing "the internalmake upof the roll;

Figure 2 is a section taken. along line II, .II of Fig, ure lg Figure 3 is a detail showingthe means for introducing and removing the drying medium to and from the drum interior;

Figure 4 is a view of a modification of the drying roll of Figure 1; and

Figure 5 is a section taken alonglines V V of Figure 4.

Briefly, my invention comprises a rotatable drum with end closures therefor by whichthe drum is supported in a suitable frame work. Adjustable partitions are positioned within the drum interior forsealing off the end supportmg one partition having threads which run in tron conversely to the'thread direction of the shaft supporting the other partition whereby when the nected shafts are rotated, the ously be moved toward or away ing upon the direction of shaft rotation. As a modification, the partitions are supported by a pair of threaded shafts, the threaded portions of the two shaft-s which supportone of the partitions having threads which run in a direction conversely to t 'e thread direct-ion of the threaded portions of the two shaftswhich supportthe other partition. When the two shafts are rotated simultaneously, the partitions will, in turn, move simultaneously toward or away from each other depending upon the direction of shaft rotation.

Referring now to the drawings, Figure 1 in particular,

interconpartitions will simultanefrom each other dependperforations 8,

. positioned over the ing 10is provided to join the rotatable pipe 5 with stationary section 5' of feed through gear 11' affixed to the end support 2.

As seen in Figures 1 through 3, a hollow shaft 15 is the roll A to a point within the drum the end of shaft 15 'and the drum interior. The portion of the shaft within the drum interior has right hand The feed pipe'5 within the drum interior is sealed off by a disc or plug 25" of the same diameter as plug 16 being Welded or otherwise secured to the end'ofpipe '5 (see Figure 3). Theend same diameter as shaft the plug 25. The opposite end of theshaft 28 '"is' similarily sealed off with plug 25" smaller diameter than shaft by inter-- a direcpipe 5] Theroll A is driven feed pipe 5 extending therealoug from i passage of pipe 5 therethrough. The plug 16 is welded to the sha-ftlS and the pipe S'whereby a water-tight seal is provided between the drum wall to effectively the drum interior from the of a hollow'shaft 28 ofthe 15is fitted over and welded to" and a shaft extension 32 of 28 is welded or otherwise"- secured to the plug 25 and extends therefrom through end support 3.

The shaft 28 has left hand running threads 33, 33 cut thereinto and a second disc partition 43 is threaded thereupon to separate the opposite end section of the drum interior from the central portion thereof. A sealing ring 19 is also positioned around the periphery of partition 43 to effectively seal off the end portion of the drum interior from the central portion thereof. The end of the shaft extension 32 beyond the end support 3 (see Figure 1) is threaded to receive a nut 35 which, when tightened against end support 3, assures rotation of the shaft extension 32, shaft 28, feed pipe 5, and shaft as a unit with the roll A.

An elongated pin 58 extends through end supports 2 and 3 and drilled aligned holes 51, 51 (Figure 2) in partitions 18 and 43 to assure rotation of the partitions as a unit with the roll A. Rubber seals 52, 52 (Figure 2) are positioned within the drilled holes 51, 51 to provide a tight seal with the pin 50 to prevent the heating medium from passing therethrough. From the above description, it, is seen that all of the units described rotate with the roll A during the drying operation.

The end of the hollow threaded shaft 15 within the drum interior has perforations 55, 55 through which excess drying medium passes into the bore of the shaft 15 (Figure 3). The medium is expelled from the end of the shaft 15 lying externally of the end support 2 (Figure 1).

As mentioned above, the position of the partitions 18 and 43 within the drum interior may be adjusted or changed as desired. This is an important feature of my invention. With this adjustable feature, the partitions 18 and 43 may be moved toward or away from each other to provide smaller or larger sealed off end areas within the roll A whereby a variety of temperature differentials between the end surface portions and the centrd surface portion of the roll A may be effected. To adjust the position of the partitions 18 and 43 within the drum interior, the operator loosens the nut 35 on the end of shaft extension 32 (Figure 1) and rotates the shaft 32 with the use of a crank in either a clockwise or counterclockwise direction to simultaneously rotate the shafts 28 and 15. Since the threads 17, direction which is converse to the thread direction of threads 33, 33 of shaft 28, the partitions will simultaneously move without rotation along the shafts toward or away from each other depending upon the direction of rotation of shaft 32. As seen in Figure 1, when the shaft extension 32 is rotated in a clockwise direction, the parti tions will converge and when the shaft extension 32 is rotated in a counter-clockwise direction, the partitions will be moved apart from one another. A collar 57 is aflixed to the end of sleeve 15 which extends beyond the end support 2 to prevent the sleeve 15 from being drawn Within the end support 2 as the nut 35 is tightened against end support 3. The adjusting of the partitions 18 and 43 is, of course, done when the roll is not in operation.

So that the operator may determine the position of the partitions 18 and 43 within the roll A, a rod 58 is afiixed to the lower portion of partition 18, the rod extending through the end support 2. Suitable indicia 59 are marked off on the end of the rod beyond the end support 2 which indicia cooperate with the straight edge 60 of the end support 2 to give a reading as to the distance between the end support 2 and the partition 18. By initially threading the partition 43 to a position on shaft 28 which corresponds to the initial position of partition 18 on shaft 15, the reading will also suffice for giving the distance between end support 3 and partition 43.

In Figures 4 and 5, there is shown a modification of the roll A of Figures 1 to 3. In this embodiment, the roll B comprises a drum 61 having end closures 62 and 63 by which the roll A is journaled in a suitable framework. The roll B is driven through gear 64 secured to end support 62. A stationary heating medium feed pipe 65 extends through the end support 62 into the drum interior and terminates at a point just beyond the drum center. The end of the pipe 65 within the drum 60 has perforations 68, 68 through which a drum heating medium is introduced into the drum interior. An adjustable hollow shaft 70 is positioned over the feed pipe 65 extends through end support 62 into the drum interior and may be moved back and forth within the end support 62. A hearing 73 is positioned between the shaft 70 and the end support 62 being secured to the end support 62 whereby friction is minimized between the sleeve and the end support during sleeve adjustment.

The end of the shaft 70 within the drum interior terminates in a flange or drum partition 75 of substantially the same diameter as the drum. A rubber ring seal 78 or other suitable seal is positioned around the periphery of partition 75 whereby the end portion of the drum interior is completely partitioned off from the central portion thereof. A disc partition 80 is positioned in the opposite end of the drum 60 and it also has a rubber ring seal 78 fitted around its periphery to seal off the opposite end portion of the drum interior from the central portion thereof. Threaded shafts 85 and 86 extend through end support 63, through threaded holes 87, 87 oppositely positioned within partition 80, through similar aligned 17 of shaft 15 run in a holes 88, 88 in partition and through end support 62. The ends of the shafts and 86 adjacent the end support 62 have threads cut thereinto which run in a right hand direction while the ends of the shafts adjacent end support 63 have threads cut thereinto which run in a left hand direction. To prevent the shafts 85 and 86 from rotating within the threaded holes 87, 87, and 88, 88 as they rotate with the drum, lock nuts 90, 90 are threaded onto the ends of the shafts extending beyond end support 63 whereby when the nuts are tightened against the end support 63, rotation of the shafts 85 and 86 within the threaded holes is prevented.

To adjust the position within the drum interior,

of the partitions 75 and 80 that is, to increase or decrease the area occupied by the drying medium, nuts 90, 90 on shafts 85 and 86 are loosened and the shafts are rotated either in a clockwise or a counter-clockwise direction to simultaneously move the partitions 75 and 80 toward or away from each other along the shafts 85 and 86. When the shafts are rotated in a counter-clockwise direction, the partitions are moved further apart and when the shafts 86 and 87 are rotated in a clockwise direction the partitions are moved closer together. With the above modifications, the shafts 85 and 86 must be rotated simultaneously so that the partitions 75 and 80 will not jam by becoming 'angularly displaced with respect to the inner surface of the drum 60.

Excess drying medium entrapped between the partitions 75 and 80 is expelled from the drum interior through the bore of sleeve 70 and may be collected as it flows from the end of sleeve 70 lying externally of the roll B.

Suitable indicia are marked on the end of hollow shaft 70 extending externally of the end sup ort 62 which. when compared with the end of su port 62 will give the distance between the end support 62 and the partition 75. By initially threading the partition 80 to a position on the rods 85 and 86 which corresponds with the initial position of partition 75 on rods 85 and 86, the reading will also suffice for giving the distance between end support 63 and partition 80.

Since the heating medium is confined to the central portion of the drum interior. the end portions of the drum surface will be of a lower temperature than the central portionsthereof when the drum is heated to drying temperature. The end surface portions of the drum will, of course, be of sufficient temperature to properly dry the end portions of a continuous sheet of cellophane passing thereover since some heat transfer will .occur along the drum surface, it is therefore obvious that the closer together thepartitions are positioned, the lower the temperatllrc Will be atthe end surface portions of the roll while the further, apart. the, p rtitions are, positioned, the higher-the temperature will: be, at theend sii'r face portions of the ten.

With the adjusting means described above, the correct or proper temperature differential may be set up within the drum by conducting several trial runs prior to the commercial production operation.

It is to be understood that changes and variations may be made without departing from the spirit or scope of the present invention as defined in the appended claims.

I claim:

1. A drying roll for drying continuously traveling sheets of flexible material comprising a rotatable hollow drum having a substantially smooth and uninterrupted surface over which the sheet travels, end supports for the drum, at least one adjustable partition within the drum for sealing off a section ofthe drum interior which partition is rotatablewith the drum, a rotatable control unit cooperating with the partition and extending through one of the end supports for adjusting the position of the partition within the drum interior which unit is capableof independent rotation other than normal drum rotation, and means extending within the drum interior for introducing a drum heating medium therewithin at a point beyond the sealed oif drum interior section.

2. A drying roll for drying continuously traveling sheets of flexible material comprising a rotatable hollow drum having a substantially smooth and uninterrupted surface over which the sheet travels, end supports for the drum, at least one adjustable partition within the drum for sealing off a section of the drum interior which partition is rotatable with the drum, a rotatable control unit cooperating with the partition and extending through one of the end supports for adjusting the position of the partition within the drum interior which unit is capable of independent rotation other than normal drum rotation, and means extending within the drum interior for introducing a drum heating medium therewithin and at a point beyond the sealed off drum interior section.

3. A drying roll for uniformly drying a continuously traveling sheet of flexible material comprising a rotatable hollow drum having a substantially smooth and uninterrupted surface over which the sheet travels, end supports for the drum, a first adjustable partition within the drum for sealing off a section of the drum interior which partition is rotatable with the drum, a second adjustable partition within the drum for sealing off a second section of the drum interior which partition is rotatable with the drum, a rotatable control unit cooperating with the partitions and extending through one of the end supports for adjusting the position of the partitions within the drum interior which unit is capable of independent rotation other than normal drum rotation, and a heating medium feed pipe extending within the drum interior for introducing a drum heating medium between the partitions.

4. A drying roll for uniformly drying a continuously traveling sheet of flexible material comprising a rotatable hollow drum having a substantially smooth and uninterrupted surface over Which the sheet travels, end supports for the drum, a first adjustable partltlon within the drum normal drum rotation, and a feed pipe extending through one end support into the drum interior for introducing a drum heating medium between the partitions.

5. A drying roll for uniformly drying a continuously traveling sheet of flexible material comprising a rotatable hollow drum having a substantially smooth and uninterrupted, surface over whichthe sheet travels, end; supports for the drum, a firstadjusta ble partition within the drum,

for. sealing 01f a section of the drum interior which parti- 7; A drying roll for uniformly-drying, a continuously the end support whereby when the roll the threaded shafts will rotate with the roll.

9. drying roll for uniformly drying a continuously 11. A drying roll for uniformly drying a continuously traveling sheet of flexible material according to claim 10 comprising lock nuts threaded over the portions of the threaded shafts extending externally of the end support which when tightened clamp the shafts to the end support to prevent individual shaft rotation when the roll is in operation.

12. A drying drum for uniformly drying a continuously traveling sheet of flexible material according to claim 10 comprising sealing rings fitted over the partition peripheries for sealing off the end sections of the drum from the central portion of the drum.

13. A drying roll for drying a continuous sheet of flexible material comprising a rotatable hollow drum having a substantially smooth and uninterrupted surface over and against which the sheet travels, at least one adjustable partition within the drum for sealing off a section of the drum which partition is rotatable with the drum, a rotatable control unit which cooperates with the partition for adjusting the position of the partition within the drum interior which unit is capable of independent rota tion other than normal drum rotation, and means for introducing a drum heating medium into the drum interior at a point beyond the sealed 01f section of the drum interior.

14. A drying roll according to claim 7 comprising a rod affixed to at least one of the disc partitions and extending through an end support, and indicia on the rod adjacent the free end of the rod.

15. A drying roll according dicia on the end of the hollow of the drum.

to claim 10 comprising inshaft extending externally References Cited in the file of this patent UNITED STATES PATENTS 

